Creating WordPress shortcodes. Basic and OOP code example

To begin, create a simple shortcode that displays the text “Hello, im shortcode text“. Place code below in your function.php file:

function basic_shortcode_function() {
    return 'Hello, im shortcode text';
}
add_shortcode('basic_shortcode', 'basic_shortcode_function');

As a result, we will get the [basic_shortcode], ready to be pasted:
on post or in php template using the function:

<?php
echo do_shortcode('[basic_shortcode]');
?>

Shortcode with with parameters

In the following example, we will create a shortcode for inserting an image with a given size.

function basic_shortcode_function2($atts) { // function of our shortcode, if there are no <strong>$atts</strong> then output an empty array

//function basic_shortcode_function2($atts = array(), $content=null) // if we want to transfer content in the body of the shortcode [shortcode]content[/shortcode]

    extract(shortcode_atts(array( //receive the data transferred to the shortcode
        'width' => 100, //set default parameters
        'height' => 100,
    ), $atts)); //pass our variable with parameters
	
    return '<img src="/image.jpg" width="' . $width . '" height="' . $height . '"/>';
}
add_shortcode('basic_shortcode2', 'basic_shortcode_function2');

Use shortcode [basic_shortcode2 width=”150″ height=”100″]. You can now pass parameters to the shortcode width=”150″ height=”100″ which will set the desired image size.

Shortcode code example on OOP

<?php

class My_Shortcodes { //create a class

    public $allCars; //declare variables for our shortcode
    public $users;

    public function register(){
        add_action('init',[$this,'register_shortcode']); //event fired after WordPress is fully loaded
    }

    public function register_shortcode(){
        add_shortcode('my_filter',[$this,'my_shortcode']); // a function that registers our shortcode my_filter
    }

    public function my_shortcode($atts = array()){ // function of our shortcode, if there are no $ atts then output an empty array
        // public function my_shortcode($atts = array(), $content=null) // if we want to transfer content in the body of the shortcode [shortcode]content[/shortcode]
        extract(shortcode_atts(array(//receive the data transferred to the shortcode
            'price' => 0, //set default parameters
            'user' => 0,
        ),$atts));//pass our variable with parameters


        $this->allCars = new allCars();

        $this->users = get_posts(array('post_type'=>'user','numberposts'=>-1)); //get all posts of type user

        $users_list = ''; // transform ours $this->users to options
        foreach($this->users as $user){
            $users_list .= '<option value="'.$user->ID.'">'.$user->post_title.'</option>';
        }

        $output = ''; // create a variable that will output the code
        $output .= '<div class="wrapper">'; // add basic html code to our variable, open our div wrapper
        $output .= '<form method="post" action="'. get_post_type_archive_link('cars') .'">'; // create a form action to cars archive page
        
       

        if($price == 1){ // If a variable $price (is passed in the shortcode) = 1
            $output .='<input type="text" placeholder="Price" name="cars_price" value="" />';  // фвdd code to our output function
        }

        
        if($user == 1){
            $output .= '
            <select name="users">
                <option value="">Select user</option>
                '.$users_list.'
            </select>
            ';
        }
        
        $output .= '<input type="submit" name="submit" value="Submit" />';

        $output .= '</form></div>';



        return $output; //output the code

        
    }

}
$My_Shortcodes = new My_Shortcodes(); //create instance
$My_Shortcodes->register(); //call the method register